How did fabric porosity affect air permeability?5 answersFabric porosity plays a crucial role in determining air permeability in various types of fabrics. The porosity of woven fabrics influences their thermal protective properties and breathability, affecting comfort and effectiveness. In polymer latex films, the pore formation and size are directly impacted by the porosity, which can be controlled by adjusting the molecular weight and dosage of added PVP molecules. Additionally, the air permeability of fabrics can be affected by the porosity changes induced by treatments like roller temperature and treatment rate, leading to variations in permeability based on fabric surface density and structural modifications. Understanding and manipulating fabric porosity are essential for optimizing air permeability in textiles used for protective garments, filters, and other applications.
What are the advantages of using porous asphalt in permeable pavement?4 answersPorous asphalt in permeable pavement offers several advantages. It provides good drainage performance and excellent skid resistance. Porous asphalt pavements allow rainwater to drain vertically and horizontally, reducing the risk of surface water accumulation. They also help to increase the coefficient of friction on the pavement surface, improving safety. Additionally, porous asphalt pavements are environmentally friendly and can help to reduce noise pollution. The use of high-viscosity modifiers and additives can further enhance the performance of porous asphalt mixtures, improving their rutting resistance, low-temperature performance, moisture sensitivity, and permeability. The addition of waste materials, such as basalt fiber and EPDM rubber, can also improve the strength and elasticity properties of porous asphalt mixtures. Overall, porous asphalt in permeable pavement offers a sustainable and effective solution for managing stormwater runoff and improving pavement performance.
What are the different permeable pavement designs or components that improves stormwater management?4 answersPermeable pavement designs or components that improve stormwater management include:
1. Using the Curve Number (CN) method within the Storm Water Management Model (SWMM) to model permeable pavements as a land cover type rather than as detention storage.
2. Long-term simulation of surface runoff to provide valuable information for the hydrologic design of permeable pavements.
3. Incorporating slight modifications within the permeable pavement system layers or innovative filters to improve contaminant removal efficiency.
4. Using maintenance procedures to mitigate clogging effects, particularly at the upper layers of the permeable pavement system.
5. Partial replacement of the permeable pavement mix design with recycled aggregates to improve permeability, although it may slightly compromise compressive strength.
6. Integrating permeable pavement with subsurface micro-detention storage to attenuate peak discharge and provide environmental benefits.
7. Evaluating the infiltration performance of permeable pavement using the Horton model, which considers the changing infiltration rate with the change of water content in the pavement media.
What is pervious concrete?5 answersPervious concrete is a type of concrete with high porosity that allows water to flow through it. It is considered an environmentally friendly material with various applications in infrastructure construction. Pervious concrete has lower strength compared to conventional concrete due to its higher porosity, but it offers several environmental benefits such as stormwater management, groundwater recharge, and mitigation of urban heat island effects. It is commonly used in low traffic areas like footpaths and parking lots. Pervious concrete can help address environmental problems by restoring groundwater levels through its draining ability. It also has the potential to be a sustainable alternative material for pavement construction. Research is being conducted to improve the strength of pervious concrete so that it can be used for more demanding applications like road pavements. Pervious concrete made with sea sand and seawater has shown acceptable properties and can be used in coastal areas with low traffic density.
What is the range of porosity of reclaimed asphalt pavement used in road pavement?3 answersThe range of porosity of reclaimed asphalt pavement (RAP) used in road pavement is not explicitly mentioned in the abstracts provided.
What are permeable pavements made of?5 answersPermeable pavements are made of various materials depending on the specific design and purpose. One type of permeable pavement includes plain soil layers, a gravel layer, a permeable concrete layer, and a modified permeable surface layer with embedded curbstone. Another type of permeable pavement is a blend of rock- and tire-derived aggregates bonded by a polyurethane binder. There is also a permeable pavement material made of a weather-resistant epoxy resin adhesive, weather-resistant resin macadam, reflective thermal insulation material, and fibers. Additionally, a layered water permeable concrete pavement can be made using waste plastic, with a water permeable concrete base layer, a broken stone layer, and a waste plastic plate layer. Furthermore, a permeable pavement system can be composed of a permeable pavement composition with a first layer of permeable pavement material and a quantity of cured carbon fiber composite material, and a second layer of a different permeable pavement material.